Some are bigger than others. The Earth's Moon is the largest compared to its mother planet, but the dwarf planet Pluto has the moon Charon which is apparently about half its size.
The Earth's Moon is about one eightieth (1/81) the mass of the Earth, with a diameter of 3476 kilometers (2160 miles). The irregular Martian moon Deimos is only 10 km in diameter at its narrowest The smallest moons of Jupiter and Saturn are even smaller, down to about 0.3 km, where the line between moonand moonlet becomes vague.
Venus has no moons.
there are 63 moons and 4 of them are big
no moons but have big craters
Mars has two very tiny moons. Jupiter and Saturn also have lots of small moons, but they also have lots of big moons.
They're fairly big for moons, although Jupiter itself is big. The four "Galilean" moons of Jupiter were the first "moons" other than our own Moon to be seen, by Galileo using his new telescope.
Because it is big
Uranus has at least 27 moons that we know of.
If you mean the moons of the planet Jupiter- there are 67 moons in total. 53 of them have names. 14 do not (yet) have a name. That's a lot of moons- but Jupiter is a BIG planet.
The biggest moon is "Ganymede" which is a moon of Jupiter.
Moons are big rocks in space so they are not created all the same way.
The four large moons on Jupiter, or Galilean moons for the astronomer who discovered them, are called Io, Europa, Ganymede, and Callisto.
because it is big planet